Locking devices which typically secure nuts in closure positions on bolts against fastened elements have had a long design history. Ideally such devices should be reusable, which is to say in their operation one-time plastic deformation of parts should be avoided. They should not require the fastened element to be retro-fitted, as for example with special locking sockets or cavities. They should achieve their positive locking effect on the nut not merely in a few discrete incremental turned positions of the nut, but precisely in that one of an infinite number of turned positions where the nut is fully closed against the fastened element. Dimensional tolerances cause play among the parts of the locking device and the nut being locked and the design of the device should neutralize that play, not only to insure that the nut remains fully closed against the fastened element but also to prevent vibration from further loosening the parts.
No prior art bolt locking device meets all of these criteria. For example U.S. Pat. Nos. 619,137, 851,964, 995,058, 1,005,727, 1,098,790, 1,181,043, 1,967,237, 2,016,000 and 2,203,219 are all examples of locking devices which positively lock a nut in a limited number of its incremental turned positions. A special retro-fitted socket or cavity is required in the fastened element in the designs of U.S. Pat. Nos. 851,964 and 1,098,790. Permanent deformation of parts preventing re-use is inherent in U.S. Pat. Nos. 619,137 and 1,967,237. None of these prior art references suggests a design specifically addressing neutralization of play among the parts of the locking assembly.
It is the principal object of this invention to combine elastically deformable biasing means with infinitely variable positive detent locking means so as to avoid plastic deformation of parts or special retro-fitting of the fastened element or elements and to achieve positive locking in an infinite number of turned positions of a nut and neutralization of play among the parts of the device.